Jumper for a calendar watch mechanism

ABSTRACT

A Jumper for a calendar watch having both day and date wheels has two arms joined together and adapted to pivot about a point proximate the junction. The structure is such that the force necessary to move the day and date wheels is minimized.

United States Patent Oki JUMPER FOR A CALENDAR WATCH MECHANISM Toshihiko Oki, Suwa, Japan Kabushiki Kaisha Suwa Seikosha, Tokyo, Japan Filed: Dec. 27, 1971 Appl. No.: 212,246

Inventor:

Assignee:

Foreign Application Priority Data Dec. 28, 1970 Japan ..45/132711 0.8. CI. ..58/58 Int. Cl. ..G04b 19/24 Field of Search ..58/57, 58, 59

References Cited UNITED STATES PATENTS 9/ l 971 Bullat ..58/58 51 Sept. 5, 1972 FOREIGN PATENTS OR APPLICATIONS 260,353 3/1949 Switzerland ..58/58 310,560 12/ l 955 Switzerland ..58/58 1,927,243 12/ l 970 Germany ..58/58 Primary Examiner-Richard B. Wilkinson Assistant Examiner-George H. Miller, Jr. Attorney-Alex Friedman et al.

[57] ABSTRACT A Jumper for a calendar watch having both day and date wheels has two arms joined together and adapted to pivot about a point proximate the junction. The

structure is such that the force necessary to move the day and date wheels is minimized.

2 Claims, 1 Drawing Figure .1 JUMPER FOR A CALENDAR WATCH MECHANISM BACKGROUND OF THE INVENTION In a calendar timepiece of conventional construction, the day and date wheels have individual jumpers consisting of a weak spring forcing a contact portion against the particular wheel. Where a separate spring is provided with each jumper it is difficult to place the jumper in position in the watch in such a position that the spring is compressed. Consequently, the spring is apt to jump from its appropriate position making it difficult to assemble such a watch automatically. Where part of the jumper is sufficiently flexible to serve as a spring it is difficult to punch out of plate material a piece sufficiently narrow so that the force exerted by the jumper against the particular wheel will not be excessive. As is evident, it is highly important that the drag imposed by the jumper be as small as possible since the drive mechanism of wrist-watches can exert only a relatively feeble force.

SUMMARY OF THE INVENTION The jumper of the present inventionis designed with two arms one of which makes contact with the day wheel and the other of which makes contact with the date wheel. At the junction of the two arms, the jumper is pivoted about a pin on a plate. The effective doubling of the length of the jumper in accordance with the present invention reduces its stiffness and makes it possible to construct the jumper of heavier material than would otherwise be the case, without exerting excessive drag on the driving mechanism of the calendar watch.

Accordingly, an object of the present invention is an improved jumper in a calendar watch which is of sturdy construction and yet imposes minimum drag on the driving mechanism of said watch.

Another object of the present invention is an improved jumper which is suitable for automatic assembly, thereby lowering costs of manufacture.

A further object of the invention is an improved jumper for a calendar watch which eliminates the need for external springs for the operation thereof.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWING For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawing, in which:

The single FIGURE is a plan view, partly broken away, of a calendar watch having therein a jumper mechanism in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A calendar watch in accordance with the present invention has a date dial 1, a day star wheel 2 secured to a day disc 3 and a day and datedriving wheel 4. Secured to day and date driving wheel 4 are date driving finger 5 and day driving finger 6.

Intermediate day driving wheel 7 is moved intermittently by day driving finger 6. Date wheel 1 is moved intermittently by driving finger 5. Jumper 8 makes contact respectively with the gear portion of date dial 1 by contact portion 8(a) and with the day star wheel 2 by contact portion 8(a). Contact portions 8(a and 8(c are mounted respectively on spring portions 8(b and 8(d). At the junction between the two arms is an aperture receiving pin 10 mounted on plate 9.

Day and date driving wheel 4 is rotated by a wheel train (not shown) operated by a suitable source of energy such as a cell or a mainspring. The rotation of driving wheel 4 causes rotation of date dial 1 by means of date driving finger 5. As aforenoted, the fact that the two arms of jumper 8 operate together decreases the effective force of jumper 8. As a result, contact 8(a) exerts only enough force against date wheel 1 to cause it to make the desired motion quickly. Next, day driving finger 6 rotates day star 2 through intermediate day wheel 7 and contact portion 8(0) of jumper 8 will provide only that force necessary to position date star wheel 2.

It is possible to adjust the entire mechanism so that both the day and the date are changed simultaneously, taking advantage of the fact that the increased length of jumper 8, pivoted at pin 10, decreases the drag on the power source sufficiently so that this can be done. Preferably, however, the mechanism is so arranged, as by adjusting the relative lengths of the two arms of jumper 8 so that the changes in the day and the date do not take place simultaneously.

The fact that a jumper designed as is jumper 8 of the present invention can exert a weaker force than a jumper of single length but of the same cross-section makes it possible to increase the spring cross-section so that the spring can be formed from a single sheet. As a consequence, the manufacturing process is simplified as is the assembly process, so that automatic assembly is made possible. Furthermore, the drag imposed by the contact portions of jumper 8 is so small that a watch employing such a jumper is not apt to stop at the instant when the day and the date are being changed.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. In a calendar timepiece having day and date wheels wherein it is desired that the pressure of a jumper against wheels be minimized, an improved jumper, comprising a first arm, a spring portion of said first arm, a contact portion at one end of said first arm,

a second arm joined to said first arm proximate the other end thereof, a spring portion of said second arm, a contact portion at the end of said second arm other than that end joined to said first arm, a plate against which said jumper rests, and a pin extending perpendicular to said plate, said jumper having a hole therethrough proximate the junction between said arms for receiving said pin, whereby said jumper can pivot about said pin, effectively allowing both arms of said jumper to act in conjunction, thereby reducing the overall stiffness of said jumper and making it possible to construct said jumper more sturdily than would otherwise be the case.

2. In a calendar timepiece having day and date wheels wherein it is desired that the pressure of a jumper against wheels be minimized, an improved jumper as defined in claim 1, wherein the length of said arms is such that said day and date wheels are moved non-simultaneously to minimize the force necessary to effect the movements. 

1. In a calendar timepiece having day and date wheels wherein it is desired that the pressure of a jumper against wheels be minimized, an improved jumper, comprising a first arm, a spring portion of said first arm, a contact portion at one end of said first arm, a second arm joined to said first arm proximate the other end thereof, a spring portion of said second arm, a contact portion at the end of said second arm other than that end joined to said first arm, a plate against which said jumper rests, and a pin extending perpendicular to said plate, said jumper having a hole therethrough proximate the junction between said arms for receiving said pin, whereby said jumper can pivot about said pin, effectively allowing both arms of said jumper to act in conjunction, thereby reducing the overall stiffness of said jumper and making it possible to construct said jumper more sturdily than would otherwise be the case.
 2. In a calendar timepiece having day and date wheels wherein it is desired that the pressure of a jumper against wheels be minimized, an improved jumper as defined in claim 1, wherein the length of said arms is such that said day and date wheels are moved non-simultaneously to minimize the force necessary to effect the moVements. 